High-frequency epilation apparatus



April E5, 1941. J. E. SCHULER ET AL 2 HIGH-FREQUENCY EPILATIQN APPARATUS Filed Nov. 8, 1939 2 Sheets-Sheet 1 75 A C Pawn? Z/A/f ZNVENTORS.

W ATTORNEYJi April 1941- J. E. SCHULER ET AL 2,238,344

HIGH-FREQUENCY EPILATION APPARATUS Filed Nov. 8, 1939 2 Sheets-Sheet 2 I i o fiLAMf/VT'? PLATE TEA/V6] f/PA/vs. La a INVENTORS.

A TTORNEY-fi Patented Apr. 15, 1941 UNITED STATES PATENT OFFICE 2.23am mon-rxaounncr EPILATION msas'rus James a. Schuler, anthem, and Arthur H.

McCleiland, 1L0! Angelou, C

aiiiL, assignors to E. 1. Dose Manufacturing Company of Calliornia, Ina, Los Angcles, Oaliih, a corporation of California Application November 8, 1939, Serial No. 304,458

'iClaims.

ing a bulb-pointed needle into the follicle containing the unwanted hair and crowdingthe high-freneedle-bulb into position adjacent the hair-bulbz the needle is then energized by high-frequency current of such intensity and for such a period of time (as controlled by the operator) as to coagulate the hair-bulb and thus "kill" the hair-root, and the dead hair may then painlessly be plucked from the follicle. The needle is removed either before or aiter abstraction oi the hair, and a new hair operated upon by a repetition of the process at a new follicle.

Efiective "killing" oi a hair-root requires de nite coagulation of the root-bulb, necessitating theuse of currents of the type and order of magnitude of those used in electro-surgical cutting apparatus. It is therefore apparent that injudicious control of the energization time of the needle on the part of the operator will result in inadequate coagulation of the hair-bulb on the one hand, or burning or cutting of the patient on the other hand. For this reason, the skill and concentration which the operator must necessarily exert places an important limitation on the number of hairs which may be removed in a given time, and many instances of serious burns and actual disfigurement have-resulted to patients, even with highly skilled operators. According to the present invention, a type of epilation apparatus is provided which removes from the scope of the operators requirements all exercise of judgment as to the length of time the coagulation current is maintained, wherefore the operator has merely to place the epilatlon needle in position in the follicle, institute the supply of current to the needle, and remove the needle and dead hair from the follicle. This change has resulted. by actual test, in doubling and even trebling the number of hairs which a skilled operator may remove in a given time. Furthermore, the device of the present invention operates to supply current sumcient for epilatlon during a limited interval of time. Thus, each time the operating switch is depressed by the operator to cause the current-supply to supply current to the needle, current sufflcient for epilation will flow through the needle for a limited interval of time, after which time the current will fall to zero or to some value insuiilcient to secure epilatlon or cause burning of the patient. This limited interval of time is relatively short, being in the neighborhood of one second or less, so that there is little opportunity for the operator to inadvertently move the needle while the current is flowing and cause burns'to the patient. At the same time, the dangers resulting from an overdosage of current are greatly minimized if not wholly eliminated. The time interval during which'a "coagulating current is supplied to the needle is caused to be independent of the length oi time during which the operator holds the operating switch depressed; hence. it relieves the operator of the burden of holding the operating switch down for a definite interval of time. These safety features and operating advantages make it possible for the operator to remove hair more rapidly and to work for longer periods of time without fatigue, and with minimized danger to the patient.

It is,-therefore,' a particular object of our invention to provide a high-frequency epilation apparatus which may be operated with a minimum danger of burning the patient.

Another object of the invention is to provide an apparatus with which epilatlon may be carand is independent ofthe length of time during which the operator maintains the operating switch in closed condition.

Further objects and advantages of our illvention will either be brought out'speciflcally in the ensuing description or will be apparent therefrom.

The above and other objects of our invention are accomplished by providing an apparatus for supplying high-frequency current to the epilatlon needle, which includes an electron discharge device having a plate and a cathode.

' The cathode is adapted to supply electrons to the plate when a potential diiference exists between the cathode and the plate. This flow of electrons causes the apparatus to supply current to the needle. Operating switch means are provided for applying a potential diflerence between the plate and cathode to cause current to be supplied to the needle with a magnitude sufilcient for epilatlon. Means are provided, in association with the operating switch means, to decrease the number oielectrons supplied by the cathode to the plate to bring the current supplied to the needle to a value below-that required for epilatlon in a limited interval of time'aiter which may be advantageously employed in the circuit illustrated in Fig. 1;

Fig. 3 is a diagrammatic illustration of an alternative power supply which may be substituted for the power supply portion of the diagram shown in Fig. l, and illustrates the use of a form of retarded relay diflerent than that shown in Fig. 2; and

Fig. 4 is a diagrammatic illustration of another alternative power supply arrangement which may be substituted for the comparable portion of Fig. 1, and illustrates the use of a reactance for defining an operating interval.

Referring now to Fig. 1, an example of our apparatus for supplying high-frequency current to an epilation needle is shown as comprising an electron discharge device ill provided with a cathode, which may comprise a filament I I, and a plate i2. Conductors i3 and II lead from the opposite sides of the filament Ii to secondary ii of a filament transformer l8, which is adapted to supply electric current to the filament, i. e., a cathode heating-current adapted to place the cathodelin electron-emitting condition. Means for applying a potential diiierence between the cathode H and the plate i2 is shown as comprising a plate transformer i1 having a secondary winding 18 which has one lead it connected to filament lead ll to provide a plate return and another lead 2! connected to one side of a plate tank coil 2!. A suitable radio frequency choke 22 is shown inserted in the lead 2|. The remaining side of the tank coil 2| is connected through a lead 23 to the plate II. The discharge device it is also provided with a grid element 24 which is connected through a lead 25 to one side of a grid coil 26. The remaining side of the grid coil 26 is connected through a conductor 21 to plate return lead it which is connected to filament lead it. A grid leak and condenser assembly 28 is shown inserted in the lead 21 to provide for the bias. A coupling condenser 28 is shown connected between the leads 21 and to provide for the feed-back between the plate and grid circuit. No condenser is shown connected across the plate tank coil 2!, since the inter-turn capacity of the coil is usually relied upon to provide the necessary capacity for resonance with the high frequency employed.

The oscillator circuit just described is conventional and is used to show the common manner in which an electron discharge device is utilized in an apparatus for supplying high-frequency current to an epilation needle. It will be obvious after reading the ensuing description that this invention is applicable to any type of high-frequency power supply which utilizes an electron discharge device as a member whose current conducting ability is required to supply current to the needle, whether it functions as an oscillator or an amplifier. Furthermore, while a conventional A.-C." circuit is shown, it will be appreciated that an equivalent D.-C." circuit could be substituted if desired.

It should now be obvious that upon energization oi the filament transformer Iii and the plate transformer i1 electrons will flow between the filament II and the plate l2 as soon as the filtement reaches a high enough temperature, and oscillations will be produced which will produce high-frequency current in the plate tank coil 28. A lead it is shown extending from an inter= mediate point on the tank coil 2| to an output terminal 2| which is adapted for connection to an epilation needle. An adjustable coupling can denser 32 is provided in the lead 36 to provide an adjustment on the amount of current fed through the terminal 3! and to isolate the patients circuit from the high-voltage power supply circuit.

With the apparatus illustratedin Fig. 1, the objects of this invention are attained particularly. by the circuit arrangement for energizing the filament and plate through their respective supply transformers i6 and I1. Leads 33 and 3d are adapted for connection to a suitable alternating current powersource, and lead 33 is shown connected to one side of primary 35 of filament transformer IS. A line switch 38 is shown inserted in the lead 32. The lead 34 is connected directly to one side of the operating coil of a relay 31. Moving contact or armature 38 of the relay 31 is connected by a suitable conductor 39 to the lead 34, and fixed contact 40 of this relay is connected to the remaining side of the primary d5 of filament transformer It. The relay 31 is shown in its normal or unenergized position, so that contacts a and 40 are connected, in which case closure of the line switch 36 completes the cir-= cuit through the primary of the filament transformer i6 and causes a flow of current through the filament II. It can now be seen that as soon as the line switch '36 is closed, the filament will be heated and the discharge device ill will be in condition to produce oscillation as soon as a potential difierence is supplied between the plate and filament, that is, as soon as the plate supply transformer is energized.

Primary ll of the plate supply transformer H has one side connected through a conductor :22

7 to thelead 34. The. other side of this primary winding is connected through a conductor in one side of a normally open operating switch ill, and the other side of this switch is connected through a lead to the remaining line lead With the portion of the circuit thus far described, the closure of the switch 44 will energize the plate supply transformer, and since the filament is already heated by the filament supply transformer which is always connected as long as the line switch 36 is closed, oscillations are set up and current may be obtained from the terminal 30.

The closing of switch 44 also operates relay 8?, since a connection 46 is provided between the remaining side of the operating coil 01' this relay and the lead l3. Thus, closure of the switch it establishes a connection from line terminal 33 through leads 4!, l3, and 48 to one side of the relay coil and directly to line terminal 3% from the other side of the coil. Energization of the relay 31 moves the armature 38 away from the contact 40 and breaks the primary circuit of the filament transformer IS. The coil of relay 3? remains energized and the armature contact 83 remains open until operating switch 44 is opened. The supply of current to the terminal 3! is not interrupted immediately upon the closing of the switch 44, but current is available at the terminal 3| practically coincidentally with the closing of the switch 44.

The interval between the time when current is available at the terminal ll. i. e.. the time, the switch 44 is closed, and the time when current is no longer available at the terminal ll after the the element ll shown in Fig. 1. The moving contact I is connected by suitable means to answitch 44 has been closed depends, among other things, upon the speed of operation of the relay ill, the resistance and reactance of the filament circuit, and the heat-storing ability of the filament. The ability of a filament or cathode to emit electrons depends upon its temperature, and the discharge device will continue to operate after the filament is deenergized until the filament cools to a temperature where insumcient electrons are emitted to sustain the discharge and cause the circuit to continue in oscillation. Thus, even if the contacts II and 4| opened simultaneously with the closing of the switch 44 and the filament circuit had no reactance, the illsment Ii may have, or may be designed to have, suificlent heat-storing capacity to cause operation of the power supply for a sufllcient length of time to produce epilation. It is generally preferable, however, to provide for a greater interval of operation than is provided by the heatstoring capacity of commercially available fllament-type electron discharge devices. For that reason we prefer to make the relay fl so that it holds the contacts ll and 4| closed for a short interval after its coil is energized by the closing of the switch 44. v

Referring to Fig. 2, we have illustrated a suitable relay which may be substituted for the relay 31 illustrated in Fig. 1. In Fig. 2, a relay 5i is shown as comprising a U-shaped iron frame member 52 to which is attached an iron pole member 53 about which is wound a relay energizing coil 54. The coil it is provided with suitable leads 55 and 58. An armature 81 is shown pivotally mounted on the U-shaped frame I and is shown carrying a heavy iron pole piece I! which is adapted to be attracted to the pole member 53 when a source of current is connected to the leads I5 and 56. Mounted on the frame member 52 and insulated therefrom is a fixed upper contact 59 which is adapted for connection with a lower moving contact II when the relay is in unenergized position, as shown. The contact til is carried by a flexible spring arm I which is attached to the armature 51 and is movable therewith. The armature 51 and the spring arm at are biased upwardly by spring 82. This spring is preferably sufliciently strong to bow the spring arm 6! upwardly, as shown in full lines in Fig. 2, so that the contacts 58 and Cl are not broken until after the armature 51 and the plate so have moved downwardly for some distance after the coil 54 is energized. In order to take full advantage of the flexure of the spring Si in causing a delay in the opening of the contacts 59 and 60, the spring 6! preferably has a normal upward bow, as shown in the dot-dash lines at The position of the armature plate II and ci'r-a the spring ii at rest when the coil '4 is energized is shown in dot-dash lines at "a and la respectively. From an inspection of Fig. 2, it may be seen that the moving contact II in moving from its full-line position to its dot-dash position 60a moves a-much shorter angular distance along a greater radius than the armature II in moving to its dot-dash position "a. Thus, the. contacts 58 and 60 do not break until the armature 58 is nearly at the end of its travel. This delays the opening of the filament circuit until some time after the coil It has been energized.

The fixed contact "is connected to a suitable lug 83, which may be connected in the place of other lug N which may be connected in the place of the moving contact 38 shown in Fig. l. Coil leads II and It may be connected to conductors 34 and I! to take the place of the coil 87 illustrated in Fig. l.

. The type of relay illustrated in Fig. 2 may be adjusted to give a greater or lesser delay by limiting the amount of flexure allowed the spring ti when the contact 60 is in connection with the contact as. This adjustment in fiexure may be provided by adjusting a set-screw which is threadedly secured to a bracket 66 carried by the armature II. It should be obvious that as the screw II is turned to increase the pressure on the spring I the amount of ilexure allowed this spring is decreased and the time interval is accordingly decreased, and vice versa.

The particular type of relay used to obtain any desired time delay is purely a matter of discretion and there are numerous relays which are available commercially for this purpose. Hence. the relay illustrated in Fig. 2 is to be taken only i as a non-limitative example of a relay which is suited for our purposes.

.Referring again to Fig. l, the operation of the power supply in connection with the process of epilation will be described briefly. A needle as used for epilation is shown at H and is provided with a bulbous end 12. A preferred form of needle is provided with an insulating coating which extends down to the bulb I2, so that the bulb aifords the only direct contact with the flesh. The needle is shown inserted within a hair follicle 13 to a depth sufiicient to bring the bulbous end 12 adjacent the hair bulb, which is not shown. The needle and the follicle are shown somewhat enlarged and somewhat ideally, for the sake of clarity. The follicle may be assumed to be located in an anatomical member 16. The needle is mounted in a suitable handle member l5 and is connected through flexible and insulated con-' iii) With the needle connected to the terminal iii and the line switch 36 closed, the operator will locate the unwanted hair and will insert the needle H into the follicle 13. When the needle has been inserted to the desired depth, the oper-- ating switch 44, which is preferably operated by foot pressure, is closed. This energizes the plate of the discharge device I and starts the flow of current suflicient for epilation through the needle II. There is usually sufflcient capacity from the body member H back to the oscillating circuit to give a return current path (such capacity coupling being indicated in dotted lines in Fig. l of the drawings, at l8 and N, i. e.', a coupling from the plate transformer to the ground to the body member)E, so that no more than one metallic connection is required between the patient and the oscillating circuit. After this current has flowed for a short time, the filament is rendered inoperative through the operation of the relay 31 and the current through the needle is either brought to zero or to a value which is too small for epilation. The needle may then be moved with impunity and will cause no damage to the patient from the standpoint of burning. No further energy will be applied to the needle as long as the foot switch 44 is down, nor will there be any flow of current through the needle ii when the foot switch 44 is opened. No further current will flow in the needle circuit until the loot switch 44 is again depressed, and the current will flow for only a short time each time this switch is depressed.

Since it is not entirely necessary to provide a time delay relay, the relay Il in Fig. 1 has been shown as a conventional relay. In Fig. 3. the power supply circuit has been shown with a conventionally illustrated time delay relay. In this figure the electron discharge device and its associated oscillator circuit have been omitted. Plate and filament transformers Ii and '2 are shown connected so that they may be energized from line leads 83 and 84 inexactly the same manner as transformers l1 and II respectively in Fig. 1.

Normally unenergized retarded relay 8! is shown with its moving contact 86 connected to its fixed upper contact 81 so that it is normally adapted to energize the filament transformer 82 when line switch 88 is closed. An operating switch is shown at 89 and is adapted when closed to energize the plate transformer 8| and relay 85 which in turn breaks the connection between Fig. 1. It is well known that the time required for the current in a circuit comprising series resistance and reactance to fall to zero is dependent upon the relative values of the resistance and reactance. The filament of the electron discharge device is shown at 9| and is placed in series with the secondary of filament transformer 93 and adjustable reactance 82. By varying the value of the reactance 92 the time required for the current in the filament circuit to fall below a value sufilcient to keep the filament at an electron-emitting temperature when the filament transformer is deenergized may be varied within certain limits. Obviously, the reactance 92 introduces a considerable voltage drop in the filament circuit. Thus the filament transformer would have to be designed to accommodate this drop.

The above-described embodiments are directed to the use of a conventional filament type thermionic (electron discharge) device, in which the mass of the cathode is relatively small wherefore the cooling-down" time during which fiow of electrons may occur from cathode to plate is quite short. Where a filament oi heavy mass is employed, or where a "heater type of tube is employed, in which the cooling-down time is of relatively greater length, the above-described procedure of establishing the plate supply in advance of the disconnection of the cathode heating current may be eliminated, and substantially simultaneous disconnection of the cathode heating current supply and connection 0! the plate supply, or even a disconnection of the oathode heating current supply in advance of the connection of the plate supply, may be established, as will be apparent to those skilled in the art. Furthermore, it will be appreciated that it is not essential that the plate circuit be wholly interrupted during the period prior to the establishment of a plate-cathode potential which is adequate for epilation, inasmuch as the existence 0! any potential low enough to insure a negligible current supply to the needle would be unobjectionable. The essential criterion is that of limiting the period of s pply or coat!- ulation" current to that which 7 adequate tor epilation, through mechanical or electrical means which are independent 01 control by the operator. wherefore the exercise of any judgment on the part 01' the operator in this connection is eliminated from the epilation procedure. The operators manualcontrol or the setting of the condenser 32,101" example, provides control of the intensity of the coagulation current, and such control enables the operatorto establish the currentfiow which secures adequate "killing of the hair-roots of a specific patient (as may readily be determined by the ease with which a coagulated hair may be withdrawn from the follicle). It will be appreciated therefore that we do not choose to consider this invention to be restricted to the specific embodiments herein delineated, and described, but rather to the scope of the subioined claims.

We claim:

1. An apparatus for supplying high-frequency current ,to an. epilation needle, which comprises: an oscillator clrcuitfadapted to supply high-frequency current to said needle, said oscillator circuit including a thermionic discharge device having a plate and a filament; filament current supply means normally connected to supply current to said filament; plate supply means for supplying current to said plate; operating switch means movable between a first positionconnecting said plate supply means to said plate and a second position disconnecting said plate supply from said plate; and filament switch means movable to a first positioninterrupting said connection between said filament current supply means and said filament in response to movement of said operating switch means to its first position and movable to a second position restoring said connection between said filament current supply means and said filament in response to movement of said operating switch means to its second position.

2. An apparatus for supplying high-frequency current to an epilation needle, which comprises: an oscillator circuit adapted to supply high-frequency current to said needle, said circuit including a thermionic discharge device having a plate and a thermionic discharge member, said discharge member when heated above a certain temperature being adapted to sustain an adequate discharge between the plate and the discharge member whena given difference in potential is applied between the plate and the discharge member and cfailse said oscillator circuit to supply current to said'n'eedle at a level adequate for epilation; operating switch means associated with said discharge device and movable between a first position causing application of said potential difierence between said plate and said dischargemember and a second position removing said potential' difi'erence between said plate and said discharge member; and switch means associated with 'said discharge device and said operating switch means and movable between a first position in which it is operable to bring the temperature of said discharge member below said temperature in response to movement of said operating switch means to its first position, and a second position in which it is operable to return-the temperature of said dischargemember to a temperature above said certain temperature in response to movement of tions between said plate supply circuit and said said operating switch means to its second position.

3. An apparatus for supplying high-frequency current to an epilation needle. which comprises: a power supply circuit including a thermionic discharge device having a plate and a filament, said circuit being adapted to supply current to said needle upon application of a potential difference between said plate and said filament; filament supply means normally connected to supply current to said filament; operating switch means operable when in one position to apply said potential dlfierence to cause said circuit to supply current to said needle with a magnitude suflicient for epilation; and switch means controlled by said operating switch means and operative to interrupt the flow of current through said filament when said operating switch means is in said one position, whereby said filament cools and said current supplied to said needle is caused to decrease, said switch means being connected to maintain the interruption of said current flow until said operating switch means is in another position.

4. An apparatus for supplying high-frequency current to an epilation needle, comprising: circuit means defining a high-frequency oscillator electrically associated with an epilation needle and including an electron-discharge device provided with an electron-emitting cathode and a plate, heating current supply means for said cathode for placing said cathode in electronemitting condition, plate current supply means, and switch means normally positioned to connect said heating current supply means to said cathode to maintain the same in electron-emitting condition while preventing supply of current to said plate from said plate current supply means and thus preventing supply of high-frequency current to said needle, said switch means being movable to another position to establish supply of current to said plate from said plate current supply means to supply high-frequency current to said needle and decrease the supply of heating current to said cathode from said heating current supply means to decrease the emission of electrons therefrom to such value as to reduce the supply of high-frequency current to said needle to a negligible value in a short period of time, said switch means being operable to maintain the decreased supply oi heating current to said cathode after such decreased supply has been established until said switch means is moved from said other position to its first-mentioned normal position.

5. An apparatus for supplying high-frequency current to an epilation needle, which comprises: an oscillator circuit adapted to supply high-frequency current to said needle, said circuit including a vacuum tube having a filament and a plate; a relay having an operating coil and cooperating movable and fixed contacts, said contacts normally engaging one another when said coil is deenergized, said coil when energized operating to hold said contacts out of engagement; a filament supply circuitfor supplying current to said filament, said circuit including said contacts and being operable to supply current only when said contacts are closed; a plate supply circuit operable to supply a potential difference between said plate and cathode when energized; connecoperating coil, whereby said operating coil is at all times energized when said plate supply is en ergized; and operating switch means operable to cause energization of said plate supply.

6. An apparatus for supplying high-frequency current to an epilation needle, which comprises: an oscillator circuit adapted to supply high-frequency current to said needle, said circuit including a vacuum tube having a filament and a plate; a relay having an operating coil and cooperating movable and fixed contacts, said contacts normally engaging one another when said coil is deenergized, said coll when energized operating to hold said contacts out of engagement; a filament transformer having a primary and a secondary, said secondary being connected in series with said filament; a series electric circuit adapted for connection to an alternating current power supply and including said primary and said contacts, said contacts operating to close said circuit when in engagement and to open said circuit when out of engagement; a plate transformer having a secondary connected to supply a potential difference between said plate and filament, and a primary; an operating switch; another series electric circuit adapted for connection to an alternating current power supply and including said plate transformer primary and said operating switch as elements thereof, said operating switch acting when closed to permit energization of said last-named circuit; and conductors connecting said operating coil in parallel with said plate transformer primary whereby said operating coil is energized at all times that said plate transformer primary is energized.

7. An apparatus for supplying high-frequency current to an epilation needle, which comprises: an oscillator circuit adapted to supply high-frequency current to said needle, said circuit including a vacuum tube having a filament and a plate; a retarded relay having an operating coil and cooperating movable and fixed contacts, said contacts normally engaging one another when said coil is deenergized, said coil when energized operating to hold said contacts out of engagement; 2. filament transformer having a primary and a secondary, said secondary being connected in series with said filament; a series electric circuit adapted for connection to an alternating current power supply and including said primary and said contacts, said contacts operating to close said circuit when in engagement and to open said circuit when out of engagement; a plate transformer having a secondary connected to supply a potential diiference between said plate and filament, and a primary; an operating switch: another series electric circuit adapted for connection to an alternating current power supply and including said plate transformer primary and said operating switch as elements thereof, said operating switch acting when closed to permit energization of said last-named circuit; and conductors connecting said operating coil in parallel with said plate transformer primary whereby said operating coil is energized at all times that said plate transformer primary is energized.

JAMES E. SCHULER. ARTHUR H. MCCLEILAND. 

